Human and divine speech share a common function but no more.
Speech transports: it transfers content from one point to another, from the inner to the outer, from a hidden to a more revealed plane.
In this regard, divine and human speech are similar.
Otherwise, however, they have nothing in common.
Just as "My thoughts are not your thoughts, nor are My ways your ways," so is divine speech separate and different from human speech.
When human speech is expressed, outwardly, it leaves the domain of the speaker and attains its own independent existence.
On the other hand, because nothing is outside the divine, divine speech is never essentially cut off from the Speaker (despite the fact that God has created an infinite distance between Himself and His speech).
Divine speech does not imply communication with another.
Rather, God is, as it were, communicating with Himself, while a prophet "overhears."
–Rabbi Adin Steinsaltz
From Learning from the Tanya by Rabbi Adin Steinsaltz